Weavable PPy/WPU/PET composite conductive fibers with high durability for multifunctional sensing applications

The development of conductive polyester (PET) fibers is of great significance in increasing their added value and application in functional textiles. However, the continuous preparation of conductive PET fibers with high strength and durability is still a challenge. In this work, polypyrrole/waterborne polyurethane (PPy/WPU)/PET composite conductive fibers (PWPFs) were continuously prepared by in-situ polymerization of blended pyrrole (Py)/WPU. The study investigated the effects of alkali concentration and treatment time on the moisture regain rate of PET fibers to improve the hydrophilicity. The effects of polymerization cycles and mass fraction of WPU on the microstructure and electrical property of PWPFs were studied. The result demonstrated that the moisture regain of PET fibers increased from 0.45 % to 1.13 % when treated in a 50 g/L NaOH solution for 6 h. A stable composite structure of WPU/PPy was formed on the surface of conductive PET fibers, prepared with 5 polymerization cycles and a WPU mass fraction of 5 wt%, achieving a resistance of 58.41 kΩ/cm. The PPy/WPU composite conductive layer partially compensated for the mechanical properties lost by PET fibers during alkaline treatment. Notably, the abrasion resistance and washing resistance of PWPFs were excellent. The conductivity of PWPFs was highly correlated with the environmental humidity, temperature, salinity, and ultraviolet light irradiation and recoverable when environmental conditions underwent cyclic changes, which demonstrated that the PWPFs could be used for multi-functional sensing applications.